Helmets assist in protecting the heads of those engaged in physical activities during which their heads are exposed to an elevated risk of injury. Amongst such activities are various sports such as ice hockey, football, baseball, rock climbing, rafting, motorcycling, etc. During many of these activities, participants (be they players, and in some cases, referees) are at risk of receiving impacts to their heads from many sources, including other participants, equipment used in the sport (for example, pucks and ice hockey sticks in case of ice hockey), or with the environment (for example, the ice or boards of an ice hockey rink, again, in case of ice hockey). Depending on the sport, and the type and the severity of these impacts, such impacts could result in injury to a participant's head. Helmets are designed to lower the risk of such impacts causing such injuries by spreading the energy of the impact over a larger surface area and by diminishing the amount of the energy which would otherwise had have to have been absorbed by the wearer's head had the wearer not been wearing the helmet. Thus, when wearing a helmet the likelihood of injury to the head of the wearer is reduced.
Typical conventional protective helmets are often designed to protect the frontal, the left temporal, the right temporal, the parietal and the occipital portions of the wearer's head. Thus, a typical such helmet has a rigid shell that surrounds these various portions of the wearer's head. The shell has a cavity therein for receiving the head of the wearer. In many conventional helmet designs, such as many ice hockey helmet designs, the rigid shell of the helmet is assembled from two separately molded plastic parts. These two parts are often adjustable one with respect to the other to reduce or enlarge the cavity within the shell for receiving the head of the wearer. This adjustability helps to provide a general overall proper fit to the helmet such that when the helmet is being worn, the shell covers the majority of the above-noted head portions and remains in place during game play.
In addition to their protective aspects, helmets must also be comfortable enough to be worn by the player throughout a game and not to unduly distract or disturb his attention during that time. Helmets obviously only provide protection when they are worn, so a certain minimum level of comfort is required to help ensure that people wear them.
One conventional way of achieving this comfort is to have a liner (typically, although not always, with various pads) attached inside the cavity of the helmet such that when a person wears the helmet the liner is disposed between the shell and the wearer's head. (Depending on its design, the liner may also play a shock-absorbing role as well, such that when the shell of the helmet receives an impact for example, the energy from this impact is at least partially absorbed by the deformation of the liner.) However, while the addition of such liners has assisted in rendering conventional helmets more comfortable to the wearer than those without, the comfort level provided by such liners is not optimal.
One possible way of improving the comfort level provided by a liner is to have the liner be adjustable to have it better conform to the head of the wearer. Typical conventional ways of adjusting such liners include both allowing the liner itself to deform and/or disposing liner adjustment mechanisms on or within the shell. Such conventional liner adjustment mechanisms typically move the liner (or portions thereof) towards or away from a particular portion of the head of the wearer under the control of the wearer. Various such adjustment mechanisms are conventionally known, but they are not without their drawbacks. In particular, a helmet cannot have too many of such mechanisms as they can (depending on their type and construction) make the helmet bulky and heavy. Further, these mechanisms tend to increase the complexity, and consequently the cost, of the design and manufacture of the helmet. Finally, notwithstanding the presence of such mechanisms, many wearers still feel that helmets should be more comfortable.
Another important design characteristic that must be taken into account is that the liner should not unnecessarily impede heat transfer from the wearer's head to the environment or external air ventilation of the wearer's head. Having multiple such conventional liner adjustment mechanisms can tend to worsen (or at least not improve) the heat transfer and ventilation aspects of conventional helmets.
Thus, helmet manufacturers (and in particular hockey helmet manufacturers) have come up with many conventional helmet designs in an attempt to balance all of these design characteristics. While many of these helmets may have provided a required degree of protection, none have been optimal in the area of comfort. There remains room for improvement in the art of helmet design, particularly as helmet liners and helmet comfort are concerned.